Is it permissible to perform the night prayer (Salat al-Layl) as four rak'ahs with a single tasleem, and what is the interpretation of the action of the Companion who used to pray 'Isha with the Prophet and then return to lead his people in prayer?

Scholars have differed regarding the manner of performing Qiyam al-Layl (night prayer):

- The first opinion: It is recommended for the worshipper to make the taslim after four rak'ahs, but if he makes the taslim after two rak'ahs, his prayer is valid (Abu Hanifa).

- The second opinion: The night prayer must be performed two rak'ahs by two rak'ahs. If one adds more than that, his prayer becomes invalid (Hanbalis and Ibn Uthaymeen).

- The third opinion: It is recommended for the night prayer to be performed two rak'ahs by two rak'ahs, but it is not obligatory. So, if one makes the taslim after four rak'ahs, his prayer is valid, although he has acted contrary to what is recommended (Malikis and Shafi'is).

As for the Companion Mu'adh ibn Jabal, who used to pray Isha with the Prophet and then return to lead his people in that same prayer, his action does not fall under the category of voluntary absolute supererogatory prayers. Rather, it falls under the category of repeating an obligatory prayer to attain a legitimate virtue, such as attending the congregation.